Leonard: Check it out. I got you a Batman cookie jar.
Sheldon: Ohhh, neat, what is the occasion?
Leonard: Well, you are a friend, and you like Batman and cookies, and you are off the team

Sheldon: Teams are traditionally named after fierce creatures, thus intimidating one's opponent.
Raj: Then we could be the Bengal Tigers.
Sheldon: Poor choice—gram for gram, no animal exceeds the relative fighting strength of the army ant.
Raj: Maybe so, but you can't incinerate a Bengal tiger with a magnifying glass

Wolowitz: Oh, more details about the new Star Trek film. There's going to be a scene depicting Spock's birth.
Raj: I'd be more interested in a scene depicting Spock's conception.
Sheldon: Oh, please. For Vulcans, mating—or if you will, pon farr—it's an extremely private matter.
Leonard: Still, I'd like to know the details. His mother was human; his father was Vulcan. They couldn't just conceive.
Wolowitz: Maybe they had to go to a clinic. Can you imagine Spock's dad in a little room with a copy of Pointy Ears and Shapely Rears?

Sheldon: I notice you're using titanium. Did you give any consideration to carbon nanotubes? They're lighter, cheaper, and have twice the tensile strength.
Wolowitz: Sheldon, there is a diploma in my office that says I have a masters in engineering.
Sheldon: And you also have a note from your mother that says, "I love you, bubulah," but neither of those is a cogent argument for titanium over nanotubes

Sheldon: 15 years old. Dennis Kim is 15 years old and he's already correcting my work. Today I went from being Wolfgang Amadeus Mozart to—you know—that other guy.
Wolowitz: Antonio Salieri.
Sheldon: Oh, God, now even you're smarter than me.

Sheldon: In Texas, when a cow stops giving milk, they don't continue feeding her. They take her out and shoot her between the eyes.
Penny: I'm confused. Did Sheldon stop giving milk?

Leonard: You always knew that someday someone would come along who was younger and smarter.
Sheldon: Yes, but I assumed I would have been dead hundreds of years and that there'd be an asterisk next to his name because he'd be a cyborg

Engineering, where the semi-skilled laborers execute the vision of those who think and dream

Sheldon

Raj [referring to Dennis Kim]: Do you know what he did? He watched me work for ten minutes and then started to design a simple piece of software that could replace me.
Leonard: Is that even possible?
Raj: As it turns out, yes

Sheldon: What happens if you use argon lasers instead of helium-neon?
Leonard: It would blow up!
Sheldon: Are you sure?
Leonard: Pretty sure...
Sheldon: Pretty sure? It's not very scientific. Is this how you normally work? Just hunches and guesses and stuff?

Raj: We need a social catalyst.
Leonard: Like what? We can't get 15-year-old girls drunk.
Wolowitz: Or can we...!?

Sheldon: Here's the problem with teleportation.
Leonard: Lay it on me.
Sheldon: Assuming a device could be invented, which would identify the quantum state of matter of an individual in one location and transmit that pattern to a distant location for reassembly. You would not have actually transported the individual, you would have destroyed him in one location and recreated him in another.
Leonard: How about that.
Sheldon: Personally, I would never use a transporter because the original Sheldon would have to be dissintegrated in order to create a new Sheldon.
Leonard: Would the new Sheldon be in any way an improvement on the old Sheldon?
Sheldon: No, he would be exactly the same.
Leonard: That is a problem

TBBT Quotes

Oh, Bernadette, please play my clarinet.

Raj's poem

Sheldon: I'll have a diet Coke.
Penny: Can you please order a cocktail? I need to practice mixing drinks.
Sheldon: Fine... I'll have a virgin Cuba Libre.
Penny: That's... rum and Coke without the rum.
Sheldon: Yes, and would you make it diet?